Add 5% (or whatever makes the assumptions work best) to the Federal tax rates. If someone at/beyond their retirement age has no assets/income, that person can get welfare payments (we can argue on the amount; perhaps a current SS-like payment). This would work like Medicaid nursing home care.

This would have a few benefits. Everyone has a safety net. There is a means test element (if you have $ you don't get the payment). For those that don't need it, you have more $ in your pocket during your working years to save/invest.